Palletized bag squeezing machine



R. E. SELTZER ETAL PALLETIZED BAG SQUEEZING MACHINE Filed Feb '7, 1956 3 Dec. 29, 1959 Sheets-Sheet 1 INVENTOR.

Jean M. Hoff Robert E. Seltzer ATTORNE Y Dec. 29, 1959 s z ETAL 2,918,863

PALLETIZED BAG SQUEEZING MACHINE 3 Sheets-Sheet 2 Filed Feb. '7, 1956 Fig. 2.

INVENTORS Jean M. Hoff Robert E. Seltzer IITTORNEY United States Patent 2,918,863 PALLETIZED BAG SQUEEZING MACHINE Robert E. Seltzer, Bellevue, Ohio, and Jean M. Hoff, YVyandotte, Mich., assignors, by direct and mesne assignments, to Wyandotte Chemicals Corporation, Wyandotte, Mich., a corporation of Michigan Application February 7, 1956, Serial No. 563,941- Claims. (Cl. 100-233) a pallet of bags in such a machine is not only compressed vertically but also horizontally.

In filling paper bags and the like with light, fluffy, powdery materials such as fine calcium carbonate, carbon black and the like, a significant quantity of air becomes entrapped in the interstices of the solid particles within the bag. In most commercial operations, the bags, packed in a rather firm condition, are stacked on their sides on a pallet. After an appropriate number of bags have accumulated to make a load, the pallet is then picked up by a lift truck and conveyed to a warehouse for storage or to a box car or the like for transportation probably to a place of storage. Under storage conditions, over a period of time, the entrapped air percolates out of the interstices and out of each bag, leaving each bag in a very loose, flabby condition whereby the pallet of bags tends to lose shape, sag and sometimes tumble, resulting in a very untidy storage condition as well as a substantial loss of storage space.

One approach to this problem is to fill the bags in a vacuum so that air does not have a chance to become entrapped within the interstices of the powder flowing into the bag during the filling operation. Machines for accomplishing this are available. However, such machines are expensive and in view of the expense many companies are reluctant to switch over from the older style of packing machines to the vacuum type.

Another approach to a solution of the problem is to follow the packing operation (which would include a bag closing step where a self-closing bag is not used) with a bag compaction operation to compress air out from the interstices of the finely divided solids and out of the bag before placing the bag in storage. Where a conveyor belt is used, for example, to deliver the bags to the warehouse, all that is needed is to pass them through a fully automatic flattener and stack them on pallets. An objection here is that the stacked pallets may not be as neat as they could be. Moreover, there are a number of cases where a conveyor type of operation is not feasible. Consequently, where a conveyor is not used, the

economics of such a bag compaction operation dictate that the bags be compressed en masse rather than individually. Hence, the compaction operation should be performed on a load of bags as, for example, by a pallet press type of machine. Indeed, even in the case where 'a conveyor and bag flattener might be used it would be desirable after stacking the bags on a pallet to place the loaded pallet in a press to shape the load and squeeze out more air.

Such pallet press type machines are known in the prior art for accomplishing one purpose oranother.

However, the prior art machines of this type, insofar as we are aware, have a disadvantage in that the pallet of bags deposited therein is compressed only in the vertical direction. No means are provided to shape up the load along the vertical sides thereof. In these days of high labor costs and fast production hardly any attempt is made in loading the pallets to manually square them up and make them neat, with the result that some bags on the pallet protrude out further than others. This not only wastes storage space but also causes a significant amount of bag damage during transportation and handling.

Also, even though such vertical compression does squeeze out most of the air from the bags, it is probable that a small proportion'of the slightly fluidized powder merely shifts horizontally and stretches the bag horizontally without the air entrapped in said powder actually being expelled therefrom. Upon removal of the pallet from the machine, each bag appears to be firm but upon storage the usual percolation of entrapped air from the interstices of the fine material occurs whereby the bagsv may not be as compact as might be desired.

In any event the bag squeezing approach is the preferred approach to the problem, particularly in the thinking of those manufacturers who use the same bag filling machine or machines for a variety of materials ranging from extremely finely divided solids to comparatively coarse granular materials which do not present the problem at hand. In their thinking it would probably be much cheaper to invest in and operate a pallet press type machine than it would be to invest in and operate a vacuum bag filling machine for only part time use.

Accordingly, it is a general object of this invention to provide a machine adapted to receive one or more pallets of bags containing slightly fluidized finely divided solids and compress substantially all air out of the individual bags stacked on said pallet or pallets while at the same time'shaping the pallet loads both horizontally and vertically.

A specific object of this invention is to adapt a pallet press machine with means to horizontally compress a pallet of bags while said pallet of bags is being simultaneously compressed vertically to thereby obtain said pallet in a permanently firm, compact, neat, squared-up condition suitable for long storage in a warehouse. It is another object of this invention to adapt pallet press machines with oppositely disposed, vertically positioned, end panels, at least 'one of which is inwardly movable and is motivated simultaneously and directly with the compression plate in traveling from its rest position to a compression position to thereby obtain compaction not only vertically but also horizontally and to thereby shape the pallet load.

These and other objects which may appear as the specification proceeds are achieved by this invention which, in

summary, comprises a palletized bag compacting and shaping machine having a frame, a compression space or chamber within said frame for receiving at least one pallet of bags for squeezing, means for vertically squeezing said pallet of bags, and means for simultaneously squeezing or compressing horizontally said pallet.

In 'a specific embodiment of this invention the compression space is formed by a horizontally arranged, stationary compression plate, a horizontally arranged, oppositely disposed, vertically movable compression plate and two oppositely disposed, vertically arranged, side panels adjacent the sides of said compression plates, at least one of said side panels being adapted to move inwardly to a vertical compression position during the movement of said plate from a rest position to a compression position with means to move said panel to andfrom said compression position Preferably, in this embodiment, a stationary, vertically arranged, back panel is provided while the front of the machine is left open to facilitate the expeditious insertion and removal of the pallets.

In a preferred embodiment of this invention the vert1- cally movable, horizontally arranged compression plate (or press plate) is positioned above the stationary horizontal compression plate (or base plate). As an additional feature, the base plate may be sectionalized to form a pallet support with at least two parallel slots of such width, length, depth and position as to be capable of receiving and accommodating the forks of a lift truck after a pallet or load (where a pallet is not used) of bags has been inserted and deposited within the compression space whereby the forks can be lowered and the lift truck backed off without the forks engaging the pallet or load. Also, it is of advantage to adapt the end panels with rounded front edges to inwardly deflect misdirected pallets being inserted into the pallet press and to reduce the possibility of damaging individual bags sticking out from the pallet loads.

Before proceeding to a description of the drawings, it should be mentioned that inasmuch as this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the embodiments to be more specifically described hereinafter are therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims and forms that are their functional as well as conjointly cooperative equivalents are intended to be embraced by those claims.

Turning now to the drawings, it will be observed that:

Fig. 1 is a front elevation in cross-section of a preferred embodiment of this invention;

Fig. 2 is a side elevation taken as along the lines 2-2 of Fig. 1;

Fig. 3 is a side view in perspective of the whole pallet press of Fig. l but with the housing and framework removed;

Fig. 4 is a top view of the apparatus shown partially in Fig. 1, said top view being taken as along the lines 44 of Fig. 1;

Fig. 5 is a top sectional view taken as along the lines 5-5 of Fig. 1; and

Fig. 6 is a partially cut away front elevation of the apparatus of Fig. 1 showing the position of the end panels and compression plate with the compression plate in a compression position.

In somewhat more detail, it will be observed that the drawings disclose a pallet press 10 having a frame and housing 12, which comprise an upright back panel member 13, an outside housing panel member 14 on each side of the press and, on each side of the press, an inside housing panel member 15 spacedly set apart from the outside housing panel member 14. Suspended at the top of the apparatus in a rest position and between the inside housing panel members 15 is a vertically movable compression plate or press plate 16 with sidewise-extending lug members 18 passing into the spacing between said housing panels 14 and 15 through a vertical slot 19 in the inside housing panel member 15 and disposed approximately along the vertical center line of the apparatus. At the bottom of the framework there will be found between the inside housing panel members 15 a stationary base plate 20 comprising a center base plate section 21 spacedly set apart from two end base plate sections 22. Each of the sections is supported by beams 23 which rest on a front ledge 24 of the pallet press housing frame and a back ledge 25 of said frame. The space 26 between each of said stationary base plate sections is of such width, depth and length as to accommodate the forks of a lift truck after a pallet of bags has been inserted into the compression space formed between the stationarybase plate 20 and the compression plate 16.

Ledges 24 and 25 are positioned a sufficient distance above the ground level to accommodate a central drive shaft 28 mounted on bearings 30 underneath the stationary base plate. Mounted on the center drive shaft 28 and located on each side of the apparatus within the spacing between the housing panels 14 and 15 are drive gears or pulleys 32 which comprise the means by which compression plate 16 is moved. Said means also comprise a speed reduction gear box and an appropriate drive motor associated with said drive shaft 23.

The means for raising and lowering the compression plate 16 also comprise a chain drive 34 located in the spacing between the housing panels 14 and 15 and having a lift chain section 35 (shown in the drawings diagrammatically as a single span chain) and a pull chain section 36 (shown in the drawings diagrammatically as a triple span chain section). The chain sections are connected to each other at their adjacent ends by a connecting means 37 which may be of a conventional type. Provided within the spacing between the housing panels 14 and 15 and at the upper end on each side of the pallet press 10 are the tension gears 46/ and the positioning gears 42. Each of these gears is adapted to receive only a single chain span, more specifically the chain section 35. These tension gears and positioning gears are diagrammatically illustrated in the drawings with the tension gear on each side of the machine located towards the rear thereof and the positioning gear on each side located adjacent the apparatus center line. On each side the lift chain section 35 attached to the pull chain section 36 passes upwardly to engage said tension gear and then passes horizontally to engage said positioning gear. From said positioning gear said chain section 35 passes downwardly along said center line towards the sidewiseextending lug members 18 whereat, by connecting means 44, the lift chain section 35 is attached to the top side of the vertically movable compression plate 16. Although it is not indicated in the drawings, it will be realized that the position of the tension gear 40 may in each case be adjusted by appropriate and conventional means to obtain the proper tension on the lift chain section 35. The three-span pull chain section 36, it will be observed, passes downwardly on each side of the apparatus from the connecting means 37 to engage the drive gear 32 and thence upwardly along the center line of the apparatus to the bottom side of the side-wise-extending lug member 18 whereat connecting means 45 are provided for attaching the pull chain section 36 to the vertically movable compression plate 16.

A unique feature of this pallet press resides in the two, oppositely disposed, vertically uprising side panels 48 each of which are shown as having along the front edges thereof an outwardly curved, extended edge member 49 for the purpose of deflecting misdirected pallets inwardly into the compression chamber. These side panels 48 should be provided with reinforcing rib members 50 which may be of triangular shape with the apex of the triangle in each case at the bottom portion of the panel. These rib members not only function to reinforce the side panels but also tend to prevent the center of gravity of the side panels from being exceeded when the panels are in compression position. The side panels 48 are hinged to the end base plate sections 22 by means of conventional hinge connections 52. At the top end of each of the side panels 48 are a pair of guide bar members 54 of said side panels and in sliding relationship with cam follower bearings 56 attached by means 57 to the vertically movable compression plate 16. At this point it should also be noted that the compression plate 16 is provided with appropriately spaced and shaped side panel openings 58 arranged to receive and pass over the side panels 48 with accompanying guide bars 54.

The end base plate sections 22, in each case, do not extend all the way to the inside housing panel members 15. This is purposely done in order that the top end of each of the side panels 48 may be defiectedoutwardly from a true vertical position to a rest position, the top end of each of the side panels 48 being adjacent its neighboring inside housing panel member while each panel is at rest position. In moving to compression position the top end of each side panel is moved inwardly to a true vertical position so that at compression position, each panel is aligned along its entire height with the vertical.

To operate the pallet press 10 a pallet loaded with bags or a load of bags in some cases is inserted into the compression chamber or space and there deposited by lowering the forks on a lift truck into the fork-receiving spaces 26. The drive motor is then energized whereby the drive shaft 28 causes the pulleys 32 to actuate the pull chain sections 36 and pull down the compression plate 16 to an appropriate compression position, as in Fig. 6, whereat the drive motor is stopped. During the downward travel of the compression plate 16, the side panels 48 are impelled inwardly from their rest position to their compression position by the cam follower bearings 56 sliding along the guide bars 54. The length of time for the side panels 48 to reach their compression position comparedto the length of time for the compression plate 16 toreach a rest position can be determined by the length and curvature of the guide bars 54; This however appears to be of minor importance since satisfactory results are obtained by bringing the side panels 48 to compression position before the compression plate reaches the compression position.

Since each pallet load inserted into the compression space will, for the same materials in the bags, have an approximate set of dimensions before and after compression, the approximate compression position of the compression plate 16 can usually be predetermined. Such predetermined compression position will depend upon the height of each loaded pallet prior to the squeezing of air from the bags thereof and the height of each loaded pallet after substantially all air has been expelled therefrom. It can probably be best determined by running several tests.

.Experience has shown it. to-be desirable for the normally encountered pallet'load to be maintained under compression for a long enough time to permit the pressurized air to escape from the compressed bags. Consequently the compression plate 16 should be left in the selected compression position for the amount of time determined to be suitable under the prevailing conditions, which time will normally be only a few seconds. The compression plate 16 is then raised as by energizing the drive motor in reverse to actuate the drive gear 32 in reverse direction whereby the lift chain 35 lifts up the compression plate 16. When the rest position of the compression plate is reached the drive motor is stopped. In the meantime, upon lifting the compression plate 16, the cam follower bearings 56 come in contact with and slidingly travel back along the guide bars 54 while the weight of the side panels 48 with their displaced centers of gravity due to the reinforcing rib members 50 causes the side panels to incline outwardly to their rest positions- It is preferred that the electrical circuit of the drive motor be arranged with appropriate automatic controls and the like so that the motor is shut off when the compression plate 16 has reached a predetermined compression position, as in Fig. 6, and, after an appropriate time lapse to enable the air to escape, to reverse the direction of the motor and raise the compression plate.

As a matter of fact, unpressed loads do vary quite a bit in their dimensions and there usually is avariation in the dimensions after compaction if a constant force on the compression plate is used, because the characteristics of the bagged materials may change from day to day" and even from hour to hour. Consequently, where automatic control means are used it is greatly preferred to use amperage control means rather than limit switches. Thus, instead of selecting a predetermined compression position for the compression plate 16, a predetermined degree of compression is selected at which degree the amperage pulled by the motor will be at a definite level. By appropriate adjustment of the amperage control means, when the amperage reaches said level, the control means will shut off the motor. In such case, a timing device should be utilized which, after a suitable time lapse, will cause the motor to be actuated in reverse to raise the compression plate.

Such automatic controls however do not form a part of this invention and, moreover, are within the skill of the art. In any event the apparatus can be operated manually with appropriate manual switches well known -to the art.

The dimensions of this apparatus will be governed by the dimensions of the normal pallet found under a given set of conditions. Typical dimensions of a pallet stacked with a normal load of bags may be taken for purposes of this description as about 40 inches wide, 48 inches long, and 50 inches high. A 40-inch by 48-inch pallet is a standard size used for both truck and car shipment. However, bags stacked on such a pallet will usually overhang an inch or so on each side before being subjected to squeezing according to this invention.

While the pallet press 10 may be dimensioned so as to receive only one pallet of bags of a given load, it is more practical to dimension the apparatus to receive two or more pallets stacked one on top of the other. Normally a two-pallet load pallet press will be satisfactory in most instances. Of course, in view of the foregoing, it will be appreciated that the distance between the side panels in compression position, which in the apparatus shown in the drawing is also the distance across the base plate 20, will be substantially the width of the pallet of bags when fully compressed.

In a commercial embodiment of the pallet press of this invention, which is currently in active and successful use, two pallet loads are inserted into the compression space, one load being positioned on top of the other. The compression plate 16 is then lowered until the desired degree of compaction is reached, this embodiment being supplied with amperage control means. After a suitable interval of time, the compression plate 16 is then raised to its rest position. As a matter of fact, in this embodiment, springs attached to the side panels 48 and to the framework and housing 12 are provided to aid in returning the side panels 48 to rest position from their compression position.

The compression operation on two pallets combined is actually preferred because with the taller initial load, the press plate 16 makes contact with the load sooner and thus exerts pressure more gradually and over a longer period of time, hence providing more time for the air to escape and minimizing the possibility of bag breakage. Further advantages of compressing at leasttwo loads at once is that less over-all time is used and less I wear is put on the machine. Once the loads have become more compact and firm and have been shaped up by this bag compaction operation, a further advantage is obtained in that both loads can be removed together from the machine as by a fork-lift truck and conveyed thereby with greater ease to the warehouse, etc.

In this particular commercial operation the compression chamber with the compression plate in rest position has a width, measured at the bottom of the apparatus along the top of the stationary, sectionalized base plate 20, of 48 /2 inches, the, height of the compression chamber, measured from the top of the center base plate section 21 to thet bottom of the compression plate 16 at rest position, is 10 feet 1 inch, and the distance from the front of the machine to the rear measured along the surface of the center base plate section 21 is 42 inches. Atypical pallet 7 loadcontaining 48 fifty-pound bags of finely divided calcium carbonate having an average particle size of about 0.1 micron measured, prior to the compaction and shaping operation, 50 inches X 42 inches X 100 inches. Following this operation the pallet load measured 48 inches X 40 inches X 60 inches. From these measurements it will be seen that the savings in storage space made possible by this invention is of a remarkable order of magnitude. Moreover, since this commercial embodiment of the invention has been in operation the appearance of the warehouse and the storage problems over a lengthy period of time were improved immeasurably over those conditions that prevailed prior to placing the pallet press into use.

Although the drawings illustrate a pallet press wherein the two side panels move from a rest position to a compression position, it will be realized that one of the side panels can be permanently mounted in compression position with the other side panel being movable. This embodiment has a major disadvantage, however, in that there is more difiiculty involved in inserting loaded pallets into the compression space. Moreover, such an embodiment does not deliver the most efficient horizontal compression to the pallet loads under compaction.

The palletized bag squeezing machine of this invention not only compresses vertically but also horizontally. In the preferred embodiment the horizontal compression force is actually exerted in two opposite directions and possibly three directions, considering the stationary back panel 13, instead of all four directions. Yet, excellent results are obtained. We have noted, however, that with the front of the machine open during the compression operation there is a tendency for one or two bags in the top layer on the pallet to break under compression when dealing particularly with paper bags and ultra-fine, easily fluidized materials. This tendency can be minimized by establishing and maintaining the bags prior to filling them at an optimum moisture content, whereat there is a high bursting strength. Seven or eight percent moisture in the paper is usually considered best. This moisture content can be established and maintained by storing the bags at 70 F. and 50% to 60% relative humidity.

What is claimed is:

l. A palletized bag squeezing and shaping machine comprising an upper, horizontally disposed, vertically movable, compression plate; a lower, stationary compression plate spacedly set apart from, and underneath said compression plate, forming thereby a compression space; means for lowering said movable compression plate from a rest position to a compression position; means for returning said compression plate to said rest position; two oppositely disposed, upright side panels adjacent the ends or" said compression plates, each of said side panels being in hinged relationship to said lower compression plate and inclined outwardly from the vertical while in rest position and being aligned with the vertical when in compression position; means for moving said side panels inwardly to a compression position while said upper compression plate is moving from its rest position to its compression position which comprises a guide bar member at the top of each of said side panels and, associated therewith in sliding relationship, a cam follower bearing attached to the underside of said upper compression plate, said upper compression plate having disposed therethrough a pair of openings of such configuration as to receive and accommodate said side panels while it is moving from its rest position to its compression position and from its said compression position back to its said rest position while said upper compression plate is travel ing from its said rest position to its said compression position; and means for returning said side panels in compression positions to their rest positions while said upper compression plate is returning from its said compression position to its said rest position.

2. A palletized bag squeezing and shaping machine said side panels to their positions of rest while said upper compression plate is returning to its position or rest comprise reinforcing rib members of said side panels on the outsides thereof, which rib members being shaped to position the center of gravity to the outside of each panel according to claim 1 wherein said means for returning when said side panels are in their compression position.

3. A palletized bag squeezing and shaping machine according to claim 1 wherein said side panels curve outwardly at their front edges whereby misdirected pallets are inwardly deflected and the possibility of bag breakage while inserting a load of bags into said compression space is minimized.

4. A palletized bag squeezing and shaping machine comprising an upper, horizontally disposed, vertically movable, compression plate, a lower stationary compression plate spacedly set apart from, and underneath said upper compression plate, forming thereby a compression space; means for lowering said movable compression plate from a rest position to a compression position; means for returning said movable compression plate to said rest position; two oppositely disposed, upright side panels adjacent the ends of said compression plates, at least one of said side panels being mounted in pivotal relationship to said stationary compression plate and inclined outwardly from said stationary compression plate while in its rest position, and aligned with the vertical when in compression position, means for moving said pivotally mounted side panel inwardly to a compression position while said movable compression plate is traveling from its rest position to its compression position comprising a sliding means associated with an inwardly directed guide means wherein said guide means is afiixecl to said pivotally mounted side panel and said sliding means is affixed to said movable compression plate; and means for returning said pivotally mounted side panel to its rest position while said movable compression plate is returning from its compression position to its rest position.

5. A palletized bag squeezing and shaping machine according to claim 4 which includes a stationary back panel adjacent the back ends of said compression plates and said side panels.

6. A palletized bag squeezing and shaping machine according to claim 4 wherein said side panels curve outwardly at their front edges whereby misdirected pallets are inwardly deflected and the possibility of bag breakage during insertion of loaded pallets into said compression space is minimized.

7. A palletized bag squeezing and shaping machine according to claim 4 wherein said means for returning the pivotally mounted side panel to its rest position while said movable compression plate is returning from its compression position to its rest position comprises reinforcing rib members disposed on the outside of said panel, which position the center of gravity to the outside of said panel when said panel is in the vertically upright position.

8. A palletized bag squeezing and shaping machine comprising an upper, horizontally disposed, vertically movable, compression plate, a lower stationary compression plate spacedly set apart from, and underneath said movable compression plate, forming thereby a compression space; means for lowering said movable compression plate from a rest position to a compression position; means for returning said movable compression plate to said rest position; two oppositely disposed, upright side panels adjacent the ends of said compression plates, at least one of said side panels being in hinged relationship to said lower compression plate and inclined outwardly from the vertical while in rest position and being aligned with the vertical when in compression position; means for moving said hinged side panel inwardly to a compression position while said vertically movable compression plate is moving from its rest position to its compression position which comprises an inwardly curved guide bar member at the top of said hinged side panel and, associated therewith in sliding relationship, a cam follower bearing attached to the underside of said vertically movable compression plate, said vertically movable compression plate having disposed therethrough at least one opening of such configuration as to receive and accommodate said hinged side panel while the vertically movable compression plate is moving from its rest position to its compression position and from its compression position to its rest position; and means for returning said hinged side panel to its rest position while said movable compression plate is returned from its compression position to its rest position.

9. A palletized bag squeezing and shaping machine according to claim 8 wherein said stationary compression plate is divided into at least three sections spacedly set apart from one another a sufiicient distance to accommodate between them the forks of a lift truck.

10. A palletized bag squeezing and shaping machine according to claim 8 wherein said means for returning said hinged side panel to its rest position from its compression position while said movable compression plate is returning to its rest position from its compression position comprises reinforcing rib members disposed on the outside of said side panel, which position the center of gravity to the outside of said hinged panel when said hinged side panel is in the vertically upright position.

References Cited in the file of this patent UNITED STATES PATENTS 164,903 Cahoon June 29, 1875 722,853 Klaus Mar. 17, 1903 801,963 Beatty Oct. 17, 1905 923,190 Luce June 1, 1909 1,257,558 Webb Feb. 26, 1918 1,257,559 Webb Feb. 26, 1918 1,721,839 Shoemaker July 23, 1929 2,351,824 Tourneau June 20, 1944 20 2,812,708 Tillinghast Nov. 12, 1957 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 2,918,863 December 29 1959 Robert E. Seltzer et a1,

Column 7, lines 69 to 71, strike out while said upper compression plate is traveling from its said rest position to its said compression position"; column 8, line '6, strike out "according to claim 1 wherein said means for returning" and insert the same before "said side panels" in line 1, same column.

Signed and s ealed this 5th day of July 1960 (SEAL) Attest:

KARL AXLINE I ROBERT c. WATSON Attesting Officer 7 Comnissioner of Patents 

